of lakewood



H. F. BRAUN ET AL FIREBOX CONSTRUCTION FOR FURNACES Oct. 4, 1932.

Filed May 3, 1928 Patented Oct. 4, 1932 UNITED STATES 'HERMAN F. BRAUN, OF LAKEWOOD, SAMUEL L. LAUGHLIN, OF CLEVELAND, ANID- PATENT OFFICE WILLIAM J. SMITH, OF LAKEWOOD, OHIO, ASSIGNOBS TO THE 'GLEVELAND STEEL PRODUCTS CORPORATION, OF CLEVELAND, OHIO, A. CORPORATION OF OHIO FIREBOX CONSTRUCTION FOR FURNACES Application filed Kay 3, 1928. Serial No. 274,930.

This invention relates generally to household furnaces and more particularly to a novel and improved firebox construction which is especially designed and adapted for use in connection with furnaces of the type in which fuel oil is atomized by a rotary atomizing nozzle and burned adjacent the periphery of the firebox in the form of a ring.

The main object of the invention is to provide a novel and eflicient firebox construction for use with rotary oil burners of the character referred to and in which a swirling flame is produced at a point spaced from the burner unit and in the shape of a ring about the peripheral wall of the firebox.

Another object of the invention is to generally improve the efficiency of heating units of this character and to provide for a thorough and efficient mixture of atomized fuel and air.

A further obj ectof the invention is to provide a firebox construction which is provided with a plurality of hearth segments of refractory material disposed about the periphery of the firebox and which are so shaped and designed as to increase the efficiency of the flame and to impart a swirling motion to the flame. v

A still further object of the invention is to provide a firebox construction of the character described in which the hearth segments are baked at a high temperature and glazed about the exposed surface so as to be impervious to oil.

Further and more limited objects of the invention will appear as the description proceeds and by reference to the accompanying drawing in which Fig. 1 is a fragmentary vertical sectional view disclosing our improved firebox construction with the hearth segments arranged therein and Fig. 2 is a horizontal sectional View disclosing the manner in which the hearth segments are arranged within the firebox.

Referring now to the drawing, reference character 1 designates the vertical side walls of the firebox or combustion chamber of the furnace and 2 designates the bottom or base member of the furnace which is preferably formed of refractory material. The base member 2 fits within the bottom of the furnace and is provided with a centrally disposed opening 3 through which projects the rotary burner unit which consists of a hollow casting 1 which projects through the opening and which is supported in any suitable manner. The burner unit projects up wardly through the opening in the base member 2 and has secured thereto a combination oil distributingmember and fan 5 having a plurality of fan blades thereon disposed about the periphery thereof. The details of the oil distributing unit are disclosed in our Patent No. 1,655,016 issued January 3, 1928 and form no part of this invention. The base member 2 is preferably annular in shape and the upper side of the same tapers upwardly and outwardly from the opening 3 to a point slightly below the plane of discharge of the fuel as shown by the arrows in Fig. 1. Arranged within the furnace and resting on the base member 2 are a plurality of sections of hearth segments 6, 7, 8, 9, 10 and 11 which, when inserted form an annular ring about the peripheral wall of the furnace. The hearth segments are shaped in section as shown most clearly in Fig. 1 so as to provide an annular depression 12 on the upper side thereof extending about the wall of the furnace. The inner side walls of the hearth segments are shaped so as to provide a depression 13 extending about the peripheral wall ofthe furnace. The hearth segments are so arranged and of such height as to be disposed in line with the discharge of fuel from the rotary distributing member. The fuel is discharged radially as indicated by the series of arrows in Fig. 1 and strikes against the side wall of the depression 13 which serves to further break up the particles of fuel which have not become atomized and to affect a most thoroughmixture of the air and fuel. Due to the speed of rotation of the combined fan and distributing head, any unatomized particles of fuel are delivered against the side wall of the depression 13 with considerable force. The air taken in by the fan and delivered through openings 14 also follows this same path.- Due to the depression 12 in the upper side of the hearth segments and due to the speed of the fan, there is a tendency to decrease the pressure within the depression 12' which serves to impart to the flame a swirling motion in the direction indi- 5 cated by the arrows in Fig. 1. The combustion takes place in the shape of an annular swirling ring about the periphery of the firebox. The depression 13 serves as a reservoir for any liquid fuel which may not become atomized or which may be delivered against the hearth segment before the fuel is ignited. As soon as the burner has been ignited fora short period the hearth segments become very hot and any liquid fuel remaining in the depression 13 will be vaporized and mixed with the air. The fuel is usually ignited by means of a pilot frame which is expanded just prior to the starting of the burner unit. The hearth segments are molded from refractory matega rial and are baked at a very high temperature dii and glazed with porcelain, salt or vitrolite. The purpose of this glazing is to render the segments impervious to oil, which is found to be advantageous in the lighting of the burner. v

- In the apparatus described it will be noted that when the same is in operation, the fuel and air are mixed and are thrown in a generally horizontal direction by the rotating distributor against the ignition or impact wall of that portion of the hearth structure lying adjacent to the inner wall of the furnacewhere the mixture is vaporized and so influenced by the said peripheral portion that combustion is initiated in a peripheral zone above the upstanding portion of the hearth structure and adjacent to the furnace wall.

It will now be clear that we have provided a firebox construction which will accomplish the objects of the invention as hereinbefore stated. Various changes may be made in the size and shape of the hearth segments without do arting from the spirit of the invention. t is tobe understood that the segments may be so shaped as to fit within the walls of a square or oblong furnace and will function in the manner herein described. Various other changes may be made in the details of our construction without departing from the spirit of our invention and we wish our invention to be limited only in accordance with the scope of the appended claims.

Having thus described our invention, what we claim is:

1. A firebox construction forv furnaces adapted for burning fuel oil and comprising a bottom member having an opening therein adapted to receive a rotar oil distributing member therethrou h, a urality of hearth segments disposed a out the periphery of the fire box and constitutin a continuous surface against which the oil rom the distributing of the fuel whereby to give a swirling motion to. the flame when the distributing member is set in motion and the oil ignited.

2. A fire box construction for furnaces adapted for burning fuel oil comprising a bottom member having an opening therein adapted to receive a rotary oil distributing member therethrough, a plurality of hearth segments disposed about the periphery of the firebox and arranged so as to constitute a continuous surface against whichthe oil from the distributing member strikes, the exposed surface of said hearth segments being glazed and impervious to oil, the upper surface of said segments having an annular depression therein disposed below the plane of discharge of the fuel thereby to impart a swirling motion to the flame when the distributing member is set in motion and the fuel ignited.

3. A firebox construction for furnaces adapted for burning fueLoil and comprising a bottom member having an opening there-- 1n adapted to receive a rotary oil distributing member therethrough, the said bottom member tapering upwardly and outwardly from said opening and an annular member disposed about the periphery of the firebox and having an annular depression therein disposed below the plane of discharge of. the

fuel; to impart a swirling motion to the flame when the distributing member is set in mov tion and the fuel ignited.

4. Ina furnace of the character described, the combination of a firebox the bottom of which is formed principally of refractory material, said bottom member having a centrally disposed opening therein, a .power operated fuel and air-distributing mechanism arranged within said opening and adapted to discharge fuel in a horizontal plane, an annular member arranged within said firebox and disposed within the plane of discharge of fuel to receive the discharge from said distributor against its inner face, said annular member having a depressed channel in the upper face thereof just beyond its inner face and disposed slightly below the plane of discharge of the fuel;

5. In a furnace of the character described. the combination of a firebox the bottom of which is formed by-a member composed principally of refractory material, said bottom member having a centrally disposed opening therein, a power operated fuel and air distributing mechanism arranged within said opening and adapted to discharge the fuel in a horizontal plane, an annular member disposed about the peripheral wall of .the' furnace andpositioned within the plane of dis charge. of fuel, theinner side wall of said member being shaped to. provide an annular depression which is disposed slightly below the plane of discharge of fuel, the upper face of said annular member having an annular depression therein wheheby to impart a swirling motion to the flame when the distributing member is rotated and the fuel ignited.

6. In a furnace of the character described the combination of a firebox the bottom of which has a centrally disposed opening therein,-a power operated fuel and air distributing mechanism arranged within said opening and adapted to discharge fuel in a horizontal plane, an annular member extending about the periphery of said firebox, the inner face of said annular member being disposed in the plane of discharge. of fuel and having an annular depression therein, the upper face of said annular member being disposed above the plane of discharge of fuel and having an annular depression therein whereby to impart a swirling motlo'n to the flame when the distributing member is set in motion and the.

fuel ignite 7. A firebox construction for oil burning furnaces of those types which are provided with centrifugally-acting distributing heads, including, a hearth extending around said distributing head at a considerable distance therefrom and including an upstanding portion having an inner surface which intersects the trajectory of fuel droplets at substantially right angles, an inner, upwardly extending projection spaced a short distance from said upstanding portion and terminating below the trajectory 'of the fuel droplets and defining between itself and said upstanding portion a narrow depression adjacent the lower edge of said surface.

8. A'firebox construction for oil burning furnaces of those types which are provided with centrifugally-acting distributing heads, including, a hearth. extending around said distribut-ing head at a considerable distance ly right angles, an inner, upwardly extending.

therefrom and including an upstanding portion having an inner surface which intersects the trajectory of fuel droplets at substantia projection spaced a short d stance from said upstanding portion and terminating below the trajectory of the fuel droplets and defining between itself and said upstanding portion a narrow depression continuous with the lower edge of said surface, said firebox being provided with a bottom immediately below said hearth and the inner surface of said upwardly extending projection rising sharption for initiating combustion in a zone at the location of said refractory portion,

1y above said bottom at a point adjacent but spaced a short distance inwardly ofsa'id depression.

9. A firebox construction for oil burning furnaces of those'types which are provided with centrifugally-acting oil and air distributing heads, including, a hearth extending around said distributing head at a cori siderable distance therefrom adjacent to the walls of the furnace, said hearth including an upstandingnon-metallic refractory porperipheral said refractory portion having an inner, glazed, oil-vaporizing surface which intersects the trajectory of oil and air at substantially ri ht angles.

10. A firebox construction for oil burning furnaces of those types which are provided with centrifugally-acting'distributing heads, including, a hearth extending around said distributing head at a considerable distance therefrom and including an upstanding portion having an inner surface which intersects the trajectory of fuel droplets atsubstantially right angles, an inner, upwardly extending project-ion spaced a short distance from said upstanding portion and terminating below the trajectory of the fuel droplets and defining between itself and said upstanding portion a narrow depression continuous with the lower edge of said surface, said first mentioned surface and the surface of said depression being glazed.

11. A firebox construction for oil burning furnaces of those types which are provided with centrifugally-acting distributing heads, including, a hearth extending around said distributing head at a considerable distance therefrom and including an upstanding portion having an inner surface which intersects the trajectory' of fuel droplets at substantially right angles, an inner, upwardly extending projection spaced a short distance from said upstanding portion and terminating below the trajectory of the fuel droplets and defining between itself and said upstanding portion-a narrow depression continuous with the lower edge of said surface, said first mentioned surface being glazed.

12. A firebox construction for oil burning furnaces of those types which are provided with centrifugally-acting distributing heads, including, a hearth extending around said distributing head at a considerable distance therefrom and including an upstanding portion having an inner surface which intersects the trajectory of fuel droplets at substantially right-angles, an inner upwardly exten ding projection spaced a short distance from said upstanding portion and terminating below the trajectory of the fuel droplets and defining between itself and said upstanding portion a narrow depression continuous with,

v the lower edge of said surface, said upstanding portion havingits inner, upper edge higher than its intermediate portion whereby a groove is formed outwardly of said inner, upper edge between the same and the furnace .wall.

13. A firebox construction for oil burning furnaces of'those types which are provided jwith centriIugally-acting distributing heads.

right angles, an inner, upwardly extending projection spaced a short distance from said upstanding portion and terminating below the trajectory of the fuel droplets and defin;

[5: ing between, itself and said upstanding portion a narrow depression continuous with the lower edge of saidsurface, said firebox being provided with a bottom immediately below said hearth and the inner surface of said upwardly extending projection rising sharply above said bottom at a point adjacent but spaced a short distance inwardly of said dcpression, said upstanding portion having itsinner, upper edge higher than its intermediate portion whereby a groove is formed out:v

wardly of said inner upper edge between the same and the furnace wall.

14. In a furnace of the character described, the combination of a fire box, the bottom of which includes a substantially annular hearth, a centrifugal distributing head projecting upwardly through said bottom, said hearth being stepped to provide two substantially vertical faces near the periphery of said bottom, one above and outward of the other, the upper said face intersecting the trajectory offuel thrown outwardly by said distributing head, the height of the upper face being substantially equal to the distance thereof from the periphery of said bottom.

15. In a furnace of the character described, I

which includes a substantially annular hearth, and a centrifugal distributing head projecting upwardl through said bottom, said hearth embo ying 'means including stepped, upstanding faces near the periphery l of said bottom adapted to cooperate witlisaid distributing head for imparting a whirling 'motion to the flame, the upper of said upstanding faces intersecting the trajectory of, fuel from said distributing head and said hearth including a depression between said faces. v

17 In a furnace of the type described, the

combination of a fire box, the bottom of which includes a substantially annular hearth, and a centrifugaldistributing head projecting'upwardly through, said bottom,

said hearth embodying means including stepped, upstanding faces near the periphery of said bottom adapted to'cooperate with said distributing head for imparting a whirling motion to the flame, the upper of said upstanding faces intersecting the trajectory of ery an element of refractory,material inter- I posed in the path of the combustible mixture said element being of stepped construction with its uppermost step provided with a 1ongitudinal groove.

19. In an 011 burning. furnace having a centrally located combustible mixture pro ecting device, a hearth comprising a substantially flat portion having at-its -periphery an element of refractory materlal interposed,

in the path of thecombustible mixture said element being of stepped construction with its uppermost step provided with a longitudinal groove, and a lower step with an oil collecting groove.

20. Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, a centrifugal projector for horizontally discharging oil and air above said hearth, and ail-element of refractory mate rial disposed adj ace-nt the inner wall of said furnace, all operating to initiate combustion in a peripheral zone at the location of said element, said element being of stepped construction with its uppermost step provided with an upwardly facing groove.

21. Apparatus of the class described, in-

eluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector for horizontally discharging oil and air above said hearth, and an element of refractory material disposed adjacent the inner wall of said furnace, all operating to initiate combustion in a peripheral zone at the location of said element, said element being of stepped construction with its uppermost step provided with an upwardly facing groove and its lower step provided with an oil collecting groove.

22. Apparatus of the class described, 1ncluding a furnace, a hearth closing in the IOL bottom thereof, a centrifugal projector for horizontally discharging oil and air above said hearth, and an element of refractory material disposed adjacent the inner wall of a said furnace, all operating to initiate combustion in a peripheral zone at the location of said element, said element having an upwardly extending portion provided with an inner surface intercepting thepath of projected oil and an upper surface above said path having an upwardly presented depression therein.

23. Apparatus of the class described, in-

cluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector for horizontally discharging oil and air above said hearth, and an element of refractory material disposed adjacent the inner wall of bottom of said fire box, a centrifugal pro- 'ector for discharging oil and air above said earth, and a horizontally arranged element of refractory material adjacent the Wall of said fire box, all operating to initiate combustion in a peripheral zone at the location of said element, said element having an upwardly extending ignition wall of a height sufiicient to intercept substantially all of the oil projected by said projector and having a substantially continuous groove adjacent to and at the base of said ignition Wall.

25. In a furnace of the character described, thecombination of a fire box, the. bottom of which is principally of refractory material and provided with a centrally disposed opening therein, and power operated fuel and air r0 ectin means arran ed within said 0 ening to discharge fuel in a generally radial direction, said bottom having atits periphery a substantially endless refractory portion including an outer upstanding projection provided with an inner face which intersects the normal trajectory of fuel discharged by said projecting means, and an inner upstanding projection provided with an upper face disposed below the normal trajector of fuel, said upstanding projec- .tions dc ning therebetween a substantially continuous depression. I 26. In a liquid fuel burning furnace, a

' hearth extending transversely between the walls of said furnace and having a central opening therein, and a centrifugal-type fuel and air projecting device extending through said opening for discharging fuel and air Within said furnace and in a generally radial path above said hearth, said hearth including a substantially endless refractory element adjacent the walls of said furnace extending upwardly from said hearth and having an impact face for intercepting the fuel and a1r discharged from said projecting device, at least portions of said element outwardly of said impact face being lower than the upper edge of said face.

27. Apparatus of the class described, 1ncluding a furnace, a hearth closing in the bottom thereof, a centrifugal projector discharging oil with an underlying main draft adjacent the upper surface of the hearth, and an element of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone at the location of said' element, the latter having upwardly extending, inwardly presented non-metallic surfaces adapted to intercept the path of the projected oil and air and deflect them while vaporizing-and producing a homogenizing effect on said oil and air. v

28. Apparatus of the class described, including a furnace, a hearth closing in the bottom thereof, a centrifugal projector radially discharging air and oil adjacent the upper surface of the hearth, and an'element of refractory material adjacent the furnace walls, all designed and operating to initiate combustion in a peripheral zone at the location of said element, the latter having upwardly extending, inwardly presented surfaces adapted to intercept the path of the projected oil and air and deflect them upwardly while vaporizing and producing a homogenizing effect on said oil and air; said parts being formed and arranged to afford an oil tight oil collecting depression below the inwardly presented surface of the burner into which excess unvaporized oil flows by gravity from said burner.

29. Apparatus of the class described, in-

cluding a fire box, an unobstructed refractory hearth closing in the bottom thereof, and a rotary head comprising a centrifugal oil sprayer and air-projector, discharging horizontally above thehearth, said hearth lying below the level of the path of the projected oil spray, designed and operating to initiate combustion at the periphery of the hearth adjacent the upwardly extending wall of the fire box, said unobstructed hearth having at the periphery an upwardly extending nonmetallic refractory ignition wall of a height sufficient to intercept substantially all of the oil projected by the projecting means.

30. Apparatus of the class described, including a fire box, an unobstructed refractory hearth closing in the bottom thereof, and a retary head comprising a centrifugal oil sprayer and air projector, discharging horizontally above the hearth, said hearth lying below the level of the path of the projected oil spray, designed and operating toinitiate combustion at the periphery of the hearth adjacent the upwardly extending wall of the fire box, said unobstructed hearth having at the periphery an upwardly extending refractory ignition wall of a height sufiicient to intercept substantially all of the oil projected by the projecting means, together with an oil tight oil collecting gutter adjacent the base of said wall.

31. In a liquid fuel burning furnace, a

. hearthextending transversely between the walls of said furnace and having acentral opening therein, and a centrifu al-type fuel and air projecting device exten ing through 6 said opening for discharging fuel and airin a generally radial path above said hearth, said hearth including a substantially endless refractory element adjacent the walls of said furnace extending upwardl from 10 said hearth and having an impact ace for intercepting the fuel, and air discharged from said projecting device, and means outwardly of said face and. near the inner wall of said furnace for producing a relatively low pres- 15 sure rzone above said element in the region between said impact face and furnacewall, whereby a flame may be maintained above said element and adjacent said furnace walls.

32. The combination with, a liquid fuel '20 burning furnace having inner heat receiving walls, ofmeans for initiating combustion of a fuel mixture in a zone adjacent to said heat receiving walls, comprisin a refractory hearth substantially closing in the bottom of I 525 said furnace and having an upstanding pe-' ripheral portion adj aceht to said heat receiving walls, said upstanding peripheral portion having a fuel impact face, and means for projecting a fuel and air mixture directly 30 against said impact face, said upstanding peripheral portion and hearth being arranged with an upwardly presenting depression disposed below the line of contact of the fuel and. air mixture with said impact face. h 35 In testimony whereof, we hereunto afix our signatures. f HERMAN F. BRAUN- SAMUEL L. LAUGHLIN. WILLIAM J. SMITH. 

